Fiber cement composite siding is a high quality building material that has many advantages over vinyl, aluminum or wood siding. One major advantage is the significantly better durability of fiber cement siding. Fiber cement siding typically includes a substrate made from wood pulp or synthetic fiber mixed with silica, hydraulic cement and water. The mixture is pressed into board form and dried. One or both major surfaces of the siding may be profiled or embossed to look like a grained or roughsawn wood or other building product, or scalloped or cut to resemble shingles. A variety of siding styles or shapes are available, including lap siding, vertical siding, soffit panels, trim boards, shaped edge shingle replicas and stone or stucco replicas, all of which may be collectively referred to as “boards”. Fiber cement siding boards are also available in a variety of sizes and thicknesses. For example, vertical siding sheets typically have a width of about 1.2 m (4 ft), lengths of about 2.5 to 3 m (8 to 10 ft) and thicknesses of about 4 to 15 mm (0.16 to 0.59 in). Fiber cement siding boards may be prefinished (e.g., primed or painted) at the factory where they are made, stored in stacks (e.g., in a warehouse at the factory or at a distributor), and delivered to a job site ready for attachment to a building. The resulting prefinished board has a primed or painted appearance immediately upon attachment.
Unfortunately, however, fiber cement siding is a much heavier substrate compared to vinyl, aluminum or wood siding products. While builders and homeowners desire the beauty and convenience of fiber cement siding, the decorative surface of a prefinished board can be visually marred of damaged during storage. If the damaged preapplied finish is merely a primer, then the consequences are not so severe. After attachment to a building, the preprimed board can be coated with a final topcoat, a step that would have been carried out in any event. However, if the damaged preapplied finish is a final topcoat, then at least the damaged portion and often the entire board will have to be refinished. This defeats the purpose of manufacturing boards with a preapplied final topcoat.
One damage mechanism is caused when the heavy boards are stacked atop one other, and the accumulated board weight damages the finish. For example, the primed or painted peaks of an embossed siding surface can be crushed, and the flattened peaks can appear as glossy spots. Manufacturers attempt to reduce such damage by placing pairs of prefinished boards in face-to-face relationship with a protective plastic or paper liner between the prefinished face surfaces. The resulting board pairs may be stacked on a pallet, e.g., at a pallet height of about 30 to about 60 cm (about 1 to about 2 ft), and if the liner has sufficient thickness it may adequately protect the surface of boards within the pallet. However, in order to maximize warehouse capacity a manufacturer or distributor may also stack multiple pallets of siding boards directly atop one another, using spacing planks to provide forklift access between each pallet. The bottom boards in such a multiple pallet stack carry the weight of all the boards that are stacked above them. In tall warehouses the weight against the bottom boards may exceed 6, 8 or even 10 kg/cm2 (85, 113 or even 142 psi), and damage to the finish on such bottom boards can be severe despite the presence of the protective liner. Also, portions of the boards beneath the spacing planks may be subjected to a more concentrated load (viz., pressure) than portions not directly beneath the spacing planks, and localized finish damage may telegraph through one or more boards directly beneath the spacing planks.
From the foregoing, it will be appreciated that what is needed in the art is a pre-finished fiber cement siding product that maintains its factory appearance during storage in multiple pallet stacks, e.g., in tall warehouses. Such siding products and methods for preparing the same are disclosed and claimed herein.